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Cycles: internal code support for anisotropic Beckmann and GGX reflection

Browse Source 
Based on:

Understanding the Masking-Shadowing Function in Microfacet-Based BRDFs
E. Heitz, Research Report 2014
This commit is contained in:
Brecht Van Lommel
2014-06-04 00:39:42 +02:00
parent 8ce1090d4e
commit ceb68e809e
6 changed files with 321 additions and 123 deletions
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8
intern/cycles/kernel/closure/bsdf_hair.h
View File

@@ -63,7 +63,7 @@ ccl_device int bsdf_hair_transmission_setup(ShaderClosure *sc)
ccl_device float3 bsdf_hair_reflection_eval_reflect(const ShaderClosure *sc, const float3 I, const float3 omega_in, float *pdf)
{
#ifdef __HAIR__
float offset = sc->offset;
float offset = sc->data2;
float3 Tg = sc->T;
#else
float offset = 0.0f;
@@ -120,7 +120,7 @@ ccl_device float3 bsdf_hair_reflection_eval_transmit(const ShaderClosure *sc, co
ccl_device float3 bsdf_hair_transmission_eval_transmit(const ShaderClosure *sc, const float3 I, const float3 omega_in, float *pdf)
{
#ifdef __HAIR__
float offset = sc->offset;
float offset = sc->data2;
float3 Tg = sc->T;
#else
float offset = 0.0f;
@@ -166,7 +166,7 @@ ccl_device float3 bsdf_hair_transmission_eval_transmit(const ShaderClosure *sc,
ccl_device int bsdf_hair_reflection_sample(const ShaderClosure *sc, float3 Ng, float3 I, float3 dIdx, float3 dIdy, float randu, float randv, float3 *eval, float3 *omega_in, float3 *domega_in_dx, float3 *domega_in_dy, float *pdf)
{
#ifdef __HAIR__
float offset = sc->offset;
float offset = sc->data2;
float3 Tg = sc->T;
#else
float offset = 0.0f;
@@ -221,7 +221,7 @@ ccl_device int bsdf_hair_reflection_sample(const ShaderClosure *sc, float3 Ng, f
ccl_device int bsdf_hair_transmission_sample(const ShaderClosure *sc, float3 Ng, float3 I, float3 dIdx, float3 dIdy, float randu, float randv, float3 *eval, float3 *omega_in, float3 *domega_in_dx, float3 *domega_in_dy, float *pdf)
{
#ifdef __HAIR__
float offset = sc->offset;
float offset = sc->data2;
float3 Tg = sc->T;
#else
float offset = 0.0f;

389
intern/cycles/kernel/closure/bsdf_microfacet.h
View File

@@ -154,18 +154,18 @@ ccl_device float approx_erfinvf_impl(float p, float q)
ccl_device float approx_erfinvf(float z)
{
float p, q, s;
float p, q, s;
if(z < 0) {
if(z < 0) {
p = -z;
q = 1 - p;
s = -1;
}
else {
}
else {
p = z;
q = 1 - z;
s = 1;
}
}
return s * approx_erfinvf_impl(p, q);
}
@@ -340,11 +340,30 @@ ccl_device_inline float3 microfacet_sample_stretched(const float3 omega_i,
/* GGX microfacet with Smith shadow-masking from:
*
* Microfacet Models for Refraction through Rough Surfaces
* B. Walter, S. R. Marschner, H. Li, K. E. Torrance, EGSR 2007 */
* B. Walter, S. R. Marschner, H. Li, K. E. Torrance, EGSR 2007
*
* Anisotropic from:
*
* Understanding the Masking-Shadowing Function in Microfacet-Based BRDFs
* E. Heitz, Research Report 2014
*
* Anisotropy is only supported for reflection currently, but adding it for
* tranmission is just a matter of copying code from reflection if needed. */
ccl_device int bsdf_microfacet_ggx_setup(ShaderClosure *sc)
{
sc->data0 = clamp(sc->data0, 0.0f, 1.0f); /* m_ag */
sc->data0 = clamp(sc->data0, 0.0f, 1.0f); /* alpha_x */
sc->data1 = sc->data0; /* alpha_y */
sc->type = CLOSURE_BSDF_MICROFACET_GGX_ID;
return SD_BSDF|SD_BSDF_HAS_EVAL|SD_BSDF_GLOSSY;
}
ccl_device int bsdf_microfacet_ggx_aniso_setup(ShaderClosure *sc)
{
sc->data0 = clamp(sc->data0, 0.0f, 1.0f); /* alpha_x */
sc->data1 = clamp(sc->data1, 0.0f, 1.0f); /* alpha_y */
sc->type = CLOSURE_BSDF_MICROFACET_GGX_ID;
@@ -353,7 +372,8 @@ ccl_device int bsdf_microfacet_ggx_setup(ShaderClosure *sc)
ccl_device int bsdf_microfacet_ggx_refraction_setup(ShaderClosure *sc)
{
sc->data0 = clamp(sc->data0, 0.0f, 1.0f); /* m_ag */
sc->data0 = clamp(sc->data0, 0.0f, 1.0f); /* alpha_x */
sc->data1 = sc->data1; /* alpha_y */
sc->type = CLOSURE_BSDF_MICROFACET_GGX_REFRACTION_ID;
@@ -362,16 +382,18 @@ ccl_device int bsdf_microfacet_ggx_refraction_setup(ShaderClosure *sc)
ccl_device void bsdf_microfacet_ggx_blur(ShaderClosure *sc, float roughness)
{
sc->data0 = fmaxf(roughness, sc->data0); /* m_ag */
sc->data0 = fmaxf(roughness, sc->data0); /* alpha_x */
sc->data1 = fmaxf(roughness, sc->data1); /* alpha_y */
}
ccl_device float3 bsdf_microfacet_ggx_eval_reflect(const ShaderClosure *sc, const float3 I, const float3 omega_in, float *pdf)
{
float m_ag = max(sc->data0, 1e-4f);
float alpha_x = sc->data0;
float alpha_y = sc->data1;
int m_refractive = sc->type == CLOSURE_BSDF_MICROFACET_GGX_REFRACTION_ID;
float3 N = sc->N;
if(m_refractive || m_ag <= 1e-4f)
if(m_refractive || fmaxf(alpha_x, alpha_y) <= 1e-4f)
return make_float3(0, 0, 0);
float cosNO = dot(N, I);
@@ -380,18 +402,60 @@ ccl_device float3 bsdf_microfacet_ggx_eval_reflect(const ShaderClosure *sc, cons
if(cosNI > 0 && cosNO > 0) {
/* get half vector */
float3 m = normalize(omega_in + I);
float alpha2 = alpha_x * alpha_y;
float D, G1o, G1i;
if(alpha_x == alpha_y) {
/* isotropic
* eq. 20: (F*G*D)/(4*in*on)
* eq. 33: first we calculate D(m) */
float cosThetaM = dot(N, m);
float cosThetaM2 = cosThetaM * cosThetaM;
float cosThetaM4 = cosThetaM2 * cosThetaM2;
float tanThetaM2 = (1 - cosThetaM2) / cosThetaM2;
D = alpha2 / (M_PI_F * cosThetaM4 * (alpha2 + tanThetaM2) * (alpha2 + tanThetaM2));
/* eq. 34: now calculate G1(i,m) and G1(o,m) */
G1o = 2 / (1 + safe_sqrtf(1 + alpha2 * (1 - cosNO * cosNO) / (cosNO * cosNO)));
G1i = 2 / (1 + safe_sqrtf(1 + alpha2 * (1 - cosNI * cosNI) / (cosNI * cosNI)));
}
else {
/* anisotropic */
float3 X, Y, Z = N;
make_orthonormals_tangent(Z, sc->T, &X, &Y);
/* distribution */
float3 local_m = make_float3(dot(X, m), dot(Y, m), dot(Z, m));
float slope_x = -local_m.x/(local_m.z*alpha_x);
float slope_y = -local_m.y/(local_m.z*alpha_y);
float slope_len = 1 + slope_x*slope_x + slope_y*slope_y;
float cosThetaM = local_m.z;
float cosThetaM2 = cosThetaM * cosThetaM;
float cosThetaM4 = cosThetaM2 * cosThetaM2;
D = 1 / ((slope_len * slope_len) * M_PI_F * alpha2 * cosThetaM4);
/* G1(i,m) and G1(o,m) */
float tanThetaO2 = (1 - cosNO * cosNO) / (cosNO * cosNO);
float cosPhiO = dot(I, X);
float sinPhiO = dot(I, Y);
float alphaO2 = (cosPhiO*cosPhiO)*(alpha_x*alpha_x) + (sinPhiO*sinPhiO)*(alpha_y*alpha_y);
alphaO2 /= cosPhiO*cosPhiO + sinPhiO*sinPhiO;
G1o = 2 / (1 + safe_sqrtf(1 + alphaO2 * tanThetaO2));
float tanThetaI2 = (1 - cosNI * cosNI) / (cosNI * cosNI);
float cosPhiI = dot(omega_in, X);
float sinPhiI = dot(omega_in, Y);
float alphaI2 = (cosPhiI*cosPhiI)*(alpha_x*alpha_x) + (sinPhiI*sinPhiI)*(alpha_y*alpha_y);
alphaI2 /= cosPhiI*cosPhiI + sinPhiI*sinPhiI;
G1i = 2 / (1 + safe_sqrtf(1 + alphaI2 * tanThetaI2));
}
/* eq. 20: (F*G*D)/(4*in*on)
* eq. 33: first we calculate D(m) */
float alpha2 = m_ag * m_ag;
float cosThetaM = dot(N, m);
float cosThetaM2 = cosThetaM * cosThetaM;
float tanThetaM2 = (1 - cosThetaM2) / cosThetaM2;
float cosThetaM4 = cosThetaM2 * cosThetaM2;
float D = alpha2 / (M_PI_F * cosThetaM4 * (alpha2 + tanThetaM2) * (alpha2 + tanThetaM2));
/* eq. 34: now calculate G1(i,m) and G1(o,m) */
float G1o = 2 / (1 + safe_sqrtf(1 + alpha2 * (1 - cosNO * cosNO) / (cosNO * cosNO)));
float G1i = 2 / (1 + safe_sqrtf(1 + alpha2 * (1 - cosNI * cosNI) / (cosNI * cosNI)));
float G = G1o * G1i;
/* eq. 20 */
@@ -414,12 +478,13 @@ ccl_device float3 bsdf_microfacet_ggx_eval_reflect(const ShaderClosure *sc, cons
ccl_device float3 bsdf_microfacet_ggx_eval_transmit(const ShaderClosure *sc, const float3 I, const float3 omega_in, float *pdf)
{
float m_ag = max(sc->data0, 1e-4f);
float m_eta = sc->data1;
float alpha_x = sc->data0;
float alpha_y = sc->data1;
float m_eta = sc->data2;
int m_refractive = sc->type == CLOSURE_BSDF_MICROFACET_GGX_REFRACTION_ID;
float3 N = sc->N;
if(!m_refractive || m_ag <= 1e-4f)
if(!m_refractive || fmaxf(alpha_x, alpha_y) <= 1e-4f)
return make_float3(0, 0, 0);
float cosNO = dot(N, I);
@@ -434,17 +499,20 @@ ccl_device float3 bsdf_microfacet_ggx_eval_transmit(const ShaderClosure *sc, con
float cosHO = dot(Ht, I);
float cosHI = dot(Ht, omega_in);
float D, G1o, G1i;
/* eq. 33: first we calculate D(m) with m=Ht: */
float alpha2 = m_ag * m_ag;
float alpha2 = alpha_x * alpha_y;
float cosThetaM = dot(N, Ht);
float cosThetaM2 = cosThetaM * cosThetaM;
float tanThetaM2 = (1 - cosThetaM2) / cosThetaM2;
float cosThetaM4 = cosThetaM2 * cosThetaM2;
float D = alpha2 / (M_PI_F * cosThetaM4 * (alpha2 + tanThetaM2) * (alpha2 + tanThetaM2));
D = alpha2 / (M_PI_F * cosThetaM4 * (alpha2 + tanThetaM2) * (alpha2 + tanThetaM2));
/* eq. 34: now calculate G1(i,m) and G1(o,m) */
float G1o = 2 / (1 + safe_sqrtf(1 + alpha2 * (1 - cosNO * cosNO) / (cosNO * cosNO)));
float G1i = 2 / (1 + safe_sqrtf(1 + alpha2 * (1 - cosNI * cosNI) / (cosNI * cosNI)));
G1o = 2 / (1 + safe_sqrtf(1 + alpha2 * (1 - cosNO * cosNO) / (cosNO * cosNO)));
G1i = 2 / (1 + safe_sqrtf(1 + alpha2 * (1 - cosNI * cosNI) / (cosNI * cosNI)));
float G = G1o * G1i;
/* probability */
@@ -464,27 +532,27 @@ ccl_device float3 bsdf_microfacet_ggx_eval_transmit(const ShaderClosure *sc, con
ccl_device int bsdf_microfacet_ggx_sample(const ShaderClosure *sc, float3 Ng, float3 I, float3 dIdx, float3 dIdy, float randu, float randv, float3 *eval, float3 *omega_in, float3 *domega_in_dx, float3 *domega_in_dy, float *pdf)
{
float m_ag = sc->data0;
float alpha_x = sc->data0;
float alpha_y = sc->data1;
int m_refractive = sc->type == CLOSURE_BSDF_MICROFACET_GGX_REFRACTION_ID;
float3 N = sc->N;
float cosNO = dot(N, I);
if(cosNO > 0) {
float3 X, Y, Z = N;
make_orthonormals(Z, &X, &Y);
if(alpha_x == alpha_y)
make_orthonormals(Z, &X, &Y);
else
make_orthonormals_tangent(Z, sc->T, &X, &Y);
/* importance sampling with distribution of visible normals. vectors are
* transformed to local space before and after */
float3 local_I;
local_I.x = dot(X, I);
local_I.y = dot(Y, I);
local_I.z = cosNO;
float3 local_I = make_float3(dot(X, I), dot(Y, I), cosNO);
float3 local_m;
float G1o;
local_m = microfacet_sample_stretched(local_I, m_ag, m_ag,
local_m = microfacet_sample_stretched(local_I, alpha_x, alpha_y,
randu, randv, false, &G1o);
float3 m = X*local_m.x + Y*local_m.y + Z*local_m.z;
@@ -499,7 +567,7 @@ ccl_device int bsdf_microfacet_ggx_sample(const ShaderClosure *sc, float3 Ng, fl
*omega_in = 2 * cosMO * m - I;
if(dot(Ng, *omega_in) > 0) {
if(m_ag <= 1e-4f) {
if(fmaxf(alpha_x, alpha_y) <= 1e-4f) {
/* some high number for MIS */
*pdf = 1e6f;
*eval = make_float3(1e6f, 1e6f, 1e6f);
@@ -507,16 +575,47 @@ ccl_device int bsdf_microfacet_ggx_sample(const ShaderClosure *sc, float3 Ng, fl
else {
/* microfacet normal is visible to this ray */
/* eq. 33 */
float alpha2 = m_ag * m_ag;
float cosThetaM2 = cosThetaM * cosThetaM;
float cosThetaM4 = cosThetaM2 * cosThetaM2;
float tanThetaM2 = 1/(cosThetaM2) - 1;
float D = alpha2 / (M_PI_F * cosThetaM4 * (alpha2 + tanThetaM2) * (alpha2 + tanThetaM2));
float alpha2 = alpha_x * alpha_y;
float D, G1i;
/* eval BRDF*cosNI */
float cosNI = dot(N, *omega_in);
/* eq. 34: now calculate G1(i,m) */
float G1i = 2 / (1 + safe_sqrtf(1 + alpha2 * (1 - cosNI * cosNI) / (cosNI * cosNI)));
if(alpha_x == alpha_y) {
/* isotropic */
float cosThetaM2 = cosThetaM * cosThetaM;
float cosThetaM4 = cosThetaM2 * cosThetaM2;
float tanThetaM2 = 1/(cosThetaM2) - 1;
D = alpha2 / (M_PI_F * cosThetaM4 * (alpha2 + tanThetaM2) * (alpha2 + tanThetaM2));
/* eval BRDF*cosNI */
float cosNI = dot(N, *omega_in);
/* eq. 34: now calculate G1(i,m) */
G1i = 2 / (1 + safe_sqrtf(1 + alpha2 * (1 - cosNI * cosNI) / (cosNI * cosNI)));
}
else {
/* anisotropic distribution */
float3 local_m = make_float3(dot(X, m), dot(Y, m), dot(Z, m));
float slope_x = -local_m.x/(local_m.z*alpha_x);
float slope_y = -local_m.y/(local_m.z*alpha_y);
float slope_len = 1 + slope_x*slope_x + slope_y*slope_y;
float cosThetaM = local_m.z;
float cosThetaM2 = cosThetaM * cosThetaM;
float cosThetaM4 = cosThetaM2 * cosThetaM2;
D = 1 / ((slope_len * slope_len) * M_PI_F * alpha2 * cosThetaM4);
/* calculate G1(i,m) */
float cosNI = dot(N, *omega_in);
float tanThetaI2 = (1 - cosNI * cosNI) / (cosNI * cosNI);
float cosPhiI = dot(*omega_in, X);
float sinPhiI = dot(*omega_in, Y);
float alphaI2 = (cosPhiI*cosPhiI)*(alpha_x*alpha_x) + (sinPhiI*sinPhiI)*(alpha_y*alpha_y);
alphaI2 /= cosPhiI*cosPhiI + sinPhiI*sinPhiI;
G1i = 2 / (1 + safe_sqrtf(1 + alphaI2 * tanThetaI2));
}
/* see eval function for derivation */
float common = (G1o * D) * 0.25f / cosNO;
@@ -540,7 +639,7 @@ ccl_device int bsdf_microfacet_ggx_sample(const ShaderClosure *sc, float3 Ng, fl
#ifdef __RAY_DIFFERENTIALS__
float3 dRdx, dRdy, dTdx, dTdy;
#endif
float m_eta = sc->data1;
float m_eta = sc->data2;
bool inside;
fresnel_dielectric(m_eta, m, I, &R, &T,
@@ -557,14 +656,14 @@ ccl_device int bsdf_microfacet_ggx_sample(const ShaderClosure *sc, float3 Ng, fl
*domega_in_dy = dTdy;
#endif
if(m_ag <= 1e-4f || fabsf(m_eta - 1.0f) < 1e-4f) {
if(fmaxf(alpha_x, alpha_y) <= 1e-4f || fabsf(m_eta - 1.0f) < 1e-4f) {
/* some high number for MIS */
*pdf = 1e6f;
*eval = make_float3(1e6f, 1e6f, 1e6f);
}
else {
/* eq. 33 */
float alpha2 = m_ag * m_ag;
float alpha2 = alpha_x * alpha_y;
float cosThetaM2 = cosThetaM * cosThetaM;
float cosThetaM4 = cosThetaM2 * cosThetaM2;
float tanThetaM2 = 1/(cosThetaM2) - 1;
@@ -602,7 +701,17 @@ ccl_device int bsdf_microfacet_ggx_sample(const ShaderClosure *sc, float3 Ng, fl
ccl_device int bsdf_microfacet_beckmann_setup(ShaderClosure *sc)
{
sc->data0 = clamp(sc->data0, 0.0f, 1.0f); /* m_ab */
sc->data0 = clamp(sc->data0, 0.0f, 1.0f); /* alpha_x */
sc->data1 = sc->data0; /* alpha_y */
sc->type = CLOSURE_BSDF_MICROFACET_BECKMANN_ID;
return SD_BSDF|SD_BSDF_HAS_EVAL|SD_BSDF_GLOSSY;
}
ccl_device int bsdf_microfacet_beckmann_aniso_setup(ShaderClosure *sc)
{
sc->data0 = clamp(sc->data0, 0.0f, 1.0f); /* alpha_x */
sc->data1 = clamp(sc->data1, 0.0f, 1.0f); /* alpha_y */
sc->type = CLOSURE_BSDF_MICROFACET_BECKMANN_ID;
return SD_BSDF|SD_BSDF_HAS_EVAL|SD_BSDF_GLOSSY;
@@ -610,7 +719,8 @@ ccl_device int bsdf_microfacet_beckmann_setup(ShaderClosure *sc)
ccl_device int bsdf_microfacet_beckmann_refraction_setup(ShaderClosure *sc)
{
sc->data0 = clamp(sc->data0, 0.0f, 1.0f); /* m_ab */
sc->data0 = clamp(sc->data0, 0.0f, 1.0f); /* alpha_x */
sc->data1 = sc->data1; /* alpha_y */
sc->type = CLOSURE_BSDF_MICROFACET_BECKMANN_REFRACTION_ID;
return SD_BSDF|SD_BSDF_HAS_EVAL|SD_BSDF_GLOSSY;
@@ -618,40 +728,84 @@ ccl_device int bsdf_microfacet_beckmann_refraction_setup(ShaderClosure *sc)
ccl_device void bsdf_microfacet_beckmann_blur(ShaderClosure *sc, float roughness)
{
sc->data0 = fmaxf(roughness, sc->data0); /* m_ab */
sc->data0 = fmaxf(roughness, sc->data0); /* alpha_x */
sc->data1 = fmaxf(roughness, sc->data1); /* alpha_y */
}
ccl_device float3 bsdf_microfacet_beckmann_eval_reflect(const ShaderClosure *sc, const float3 I, const float3 omega_in, float *pdf)
{
float m_ab = max(sc->data0, 1e-4f);
float alpha_x = sc->data0;
float alpha_y = sc->data1;
int m_refractive = sc->type == CLOSURE_BSDF_MICROFACET_BECKMANN_REFRACTION_ID;
float3 N = sc->N;
if(m_refractive || m_ab <= 1e-4f)
if(m_refractive || fmaxf(alpha_x, alpha_y) <= 1e-4f)
return make_float3(0, 0, 0);
float cosNO = dot(N, I);
float cosNI = dot(N, omega_in);
if(cosNO > 0 && cosNI > 0) {
/* get half vector */
float3 m = normalize(omega_in + I);
/* get half vector */
float3 m = normalize(omega_in + I);
/* eq. 20: (F*G*D)/(4*in*on)
* eq. 25: first we calculate D(m) */
float alpha2 = m_ab * m_ab;
float cosThetaM = dot(N, m);
float cosThetaM2 = cosThetaM * cosThetaM;
float tanThetaM2 = (1 - cosThetaM2) / cosThetaM2;
float cosThetaM4 = cosThetaM2 * cosThetaM2;
float D = expf(-tanThetaM2 / alpha2) / (M_PI_F * alpha2 * cosThetaM4);
float alpha2 = alpha_x * alpha_y;
float D, G1o, G1i;
/* eq. 26, 27: now calculate G1(i,m) and G1(o,m) */
float ao = 1 / (m_ab * safe_sqrtf((1 - cosNO * cosNO) / (cosNO * cosNO)));
float ai = 1 / (m_ab * safe_sqrtf((1 - cosNI * cosNI) / (cosNI * cosNI)));
float G1o = ao < 1.6f ? (3.535f * ao + 2.181f * ao * ao) / (1 + 2.276f * ao + 2.577f * ao * ao) : 1.0f;
float G1i = ai < 1.6f ? (3.535f * ai + 2.181f * ai * ai) / (1 + 2.276f * ai + 2.577f * ai * ai) : 1.0f;
float G = G1o * G1i;
if(alpha_x == alpha_y) {
/* isotropic
* eq. 20: (F*G*D)/(4*in*on)
* eq. 25: first we calculate D(m) */
float cosThetaM = dot(N, m);
float cosThetaM2 = cosThetaM * cosThetaM;
float tanThetaM2 = (1 - cosThetaM2) / cosThetaM2;
float cosThetaM4 = cosThetaM2 * cosThetaM2;
D = expf(-tanThetaM2 / alpha2) / (M_PI_F * alpha2 * cosThetaM4);
/* eq. 26, 27: now calculate G1(i,m) and G1(o,m) */
float ao = 1 / (alpha_x * safe_sqrtf((1 - cosNO * cosNO) / (cosNO * cosNO)));
float ai = 1 / (alpha_x * safe_sqrtf((1 - cosNI * cosNI) / (cosNI * cosNI)));
G1o = ao < 1.6f ? (3.535f * ao + 2.181f * ao * ao) / (1 + 2.276f * ao + 2.577f * ao * ao) : 1.0f;
G1i = ai < 1.6f ? (3.535f * ai + 2.181f * ai * ai) / (1 + 2.276f * ai + 2.577f * ai * ai) : 1.0f;
}
else {
/* anisotropic */
float3 X, Y, Z = N;
make_orthonormals_tangent(Z, sc->T, &X, &Y);
/* distribution */
float3 local_m = make_float3(dot(X, m), dot(Y, m), dot(Z, m));
float slope_x = -local_m.x/(local_m.z*alpha_x);
float slope_y = -local_m.y/(local_m.z*alpha_y);
float cosThetaM = local_m.z;
float cosThetaM2 = cosThetaM * cosThetaM;
float cosThetaM4 = cosThetaM2 * cosThetaM2;
D = expf(-slope_x*slope_x - slope_y*slope_y) / (M_PI_F * alpha2 * cosThetaM4);
/* G1(i,m) and G1(o,m) */
float tanThetaO2 = (1 - cosNO * cosNO) / (cosNO * cosNO);
float cosPhiO = dot(I, X);
float sinPhiO = dot(I, Y);
float alphaO2 = (cosPhiO*cosPhiO)*(alpha_x*alpha_x) + (sinPhiO*sinPhiO)*(alpha_y*alpha_y);
alphaO2 /= cosPhiO*cosPhiO + sinPhiO*sinPhiO;
float tanThetaI2 = (1 - cosNI * cosNI) / (cosNI * cosNI);
float cosPhiI = dot(omega_in, X);
float sinPhiI = dot(omega_in, Y);
float alphaI2 = (cosPhiI*cosPhiI)*(alpha_x*alpha_x) + (sinPhiI*sinPhiI)*(alpha_y*alpha_y);
alphaI2 /= cosPhiI*cosPhiI + sinPhiI*sinPhiI;
float ao = 1 / (safe_sqrtf(alphaO2 * tanThetaO2));
float ai = 1 / (safe_sqrtf(alphaI2 * tanThetaI2));
G1o = ao < 1.6f ? (3.535f * ao + 2.181f * ao * ao) / (1 + 2.276f * ao + 2.577f * ao * ao) : 1.0f;
G1i = ai < 1.6f ? (3.535f * ai + 2.181f * ai * ai) / (1 + 2.276f * ai + 2.577f * ai * ai) : 1.0f;
}
float G = G1o * G1i;
/* eq. 20 */
float common = D * 0.25f / cosNO;
@@ -673,12 +827,13 @@ ccl_device float3 bsdf_microfacet_beckmann_eval_reflect(const ShaderClosure *sc,
ccl_device float3 bsdf_microfacet_beckmann_eval_transmit(const ShaderClosure *sc, const float3 I, const float3 omega_in, float *pdf)
{
float m_ab = max(sc->data0, 1e-4f);
float m_eta = sc->data1;
float alpha_x = sc->data0;
float alpha_y = sc->data1;
float m_eta = sc->data2;
int m_refractive = sc->type == CLOSURE_BSDF_MICROFACET_BECKMANN_REFRACTION_ID;
float3 N = sc->N;
if(!m_refractive || m_ab <= 1e-4f)
if(!m_refractive || fmaxf(alpha_x, alpha_y) <= 1e-4f)
return make_float3(0, 0, 0);
float cosNO = dot(N, I);
@@ -694,7 +849,7 @@ ccl_device float3 bsdf_microfacet_beckmann_eval_transmit(const ShaderClosure *sc
float cosHI = dot(Ht, omega_in);
/* eq. 33: first we calculate D(m) with m=Ht: */
float alpha2 = m_ab * m_ab;
float alpha2 = alpha_x * alpha_y;
float cosThetaM = min(dot(N, Ht), 1.0f);
float cosThetaM2 = cosThetaM * cosThetaM;
float tanThetaM2 = (1 - cosThetaM2) / cosThetaM2;
@@ -702,8 +857,8 @@ ccl_device float3 bsdf_microfacet_beckmann_eval_transmit(const ShaderClosure *sc
float D = expf(-tanThetaM2 / alpha2) / (M_PI_F * alpha2 * cosThetaM4);
/* eq. 26, 27: now calculate G1(i,m) and G1(o,m) */
float ao = 1 / (m_ab * safe_sqrtf((1 - cosNO * cosNO) / (cosNO * cosNO)));
float ai = 1 / (m_ab * safe_sqrtf((1 - cosNI * cosNI) / (cosNI * cosNI)));
float ao = 1 / (alpha_x * safe_sqrtf((1 - cosNO * cosNO) / (cosNO * cosNO)));
float ai = 1 / (alpha_x * safe_sqrtf((1 - cosNI * cosNI) / (cosNI * cosNI)));
float G1o = ao < 1.6f ? (3.535f * ao + 2.181f * ao * ao) / (1 + 2.276f * ao + 2.577f * ao * ao) : 1.0f;
float G1i = ai < 1.6f ? (3.535f * ai + 2.181f * ai * ai) / (1 + 2.276f * ai + 2.577f * ai * ai) : 1.0f;
float G = G1o * G1i;
@@ -725,27 +880,27 @@ ccl_device float3 bsdf_microfacet_beckmann_eval_transmit(const ShaderClosure *sc
ccl_device int bsdf_microfacet_beckmann_sample(const ShaderClosure *sc, float3 Ng, float3 I, float3 dIdx, float3 dIdy, float randu, float randv, float3 *eval, float3 *omega_in, float3 *domega_in_dx, float3 *domega_in_dy, float *pdf)
{
float m_ab = sc->data0;
float alpha_x = sc->data0;
float alpha_y = sc->data1;
int m_refractive = sc->type == CLOSURE_BSDF_MICROFACET_BECKMANN_REFRACTION_ID;
float3 N = sc->N;
float cosNO = dot(N, I);
if(cosNO > 0) {
float3 X, Y, Z = N;
make_orthonormals(Z, &X, &Y);
if(alpha_x == alpha_y)
make_orthonormals(Z, &X, &Y);
else
make_orthonormals_tangent(Z, sc->T, &X, &Y);
/* importance sampling with distribution of visible normals. vectors are
* transformed to local space before and after */
float3 local_I;
local_I.x = dot(X, I);
local_I.y = dot(Y, I);
local_I.z = cosNO;
float3 local_I = make_float3(dot(X, I), dot(Y, I), cosNO);
float3 local_m;
float G1o;
local_m = microfacet_sample_stretched(local_I, m_ab, m_ab,
local_m = microfacet_sample_stretched(local_I, alpha_x, alpha_x,
randu, randv, true, &G1o);
float3 m = X*local_m.x + Y*local_m.y + Z*local_m.z;
@@ -760,7 +915,7 @@ ccl_device int bsdf_microfacet_beckmann_sample(const ShaderClosure *sc, float3 N
*omega_in = 2 * cosMO * m - I;
if(dot(Ng, *omega_in) > 0) {
if(m_ab <= 1e-4f) {
if(fmaxf(alpha_x, alpha_y) <= 1e-4f) {
/* some high number for MIS */
*pdf = 1e6f;
*eval = make_float3(1e6f, 1e6f, 1e6f);
@@ -768,18 +923,48 @@ ccl_device int bsdf_microfacet_beckmann_sample(const ShaderClosure *sc, float3 N
else {
/* microfacet normal is visible to this ray
* eq. 25 */
float alpha2 = m_ab * m_ab;
float cosThetaM2 = cosThetaM * cosThetaM;
float cosThetaM4 = cosThetaM2 * cosThetaM2;
float tanThetaM2 = 1/(cosThetaM2) - 1;
float D = expf(-tanThetaM2 / alpha2) / (M_PI_F * alpha2 * cosThetaM4);
float alpha2 = alpha_x * alpha_y;
float D, G1i;
/* eval BRDF*cosNI */
float cosNI = dot(N, *omega_in);
if(alpha_x == alpha_y) {
/* istropic distribution */
float cosThetaM2 = cosThetaM * cosThetaM;
float cosThetaM4 = cosThetaM2 * cosThetaM2;
float tanThetaM2 = 1/(cosThetaM2) - 1;
D = expf(-tanThetaM2 / alpha2) / (M_PI_F * alpha2 * cosThetaM4);
/* eval BRDF*cosNI */
float cosNI = dot(N, *omega_in);
/* eq. 26, 27: now calculate G1(i,m) */
float ai = 1 / (alpha_x * safe_sqrtf((1 - cosNI * cosNI) / (cosNI * cosNI)));
G1i = ai < 1.6f ? (3.535f * ai + 2.181f * ai * ai) / (1 + 2.276f * ai + 2.577f * ai * ai) : 1.0f;
}
else {
/* anisotropic distribution */
float3 local_m = make_float3(dot(X, m), dot(Y, m), dot(Z, m));
float slope_x = -local_m.x/(local_m.z*alpha_x);
float slope_y = -local_m.y/(local_m.z*alpha_y);
float cosThetaM = local_m.z;
float cosThetaM2 = cosThetaM * cosThetaM;
float cosThetaM4 = cosThetaM2 * cosThetaM2;
D = expf(-slope_x*slope_x - slope_y*slope_y) / (M_PI_F * alpha2 * cosThetaM4);
/* G1(i,m) */
float cosNI = dot(N, *omega_in);
float tanThetaI2 = (1 - cosNI * cosNI) / (cosNI * cosNI);
float cosPhiI = dot(*omega_in, X);
float sinPhiI = dot(*omega_in, Y);
float alphaI2 = (cosPhiI*cosPhiI)*(alpha_x*alpha_x) + (sinPhiI*sinPhiI)*(alpha_y*alpha_y);
alphaI2 /= cosPhiI*cosPhiI + sinPhiI*sinPhiI;
float ai = 1 / (safe_sqrtf(alphaI2 * tanThetaI2));
G1i = ai < 1.6f ? (3.535f * ai + 2.181f * ai * ai) / (1 + 2.276f * ai + 2.577f * ai * ai) : 1.0f;
}
/* eq. 26, 27: now calculate G1(i,m) */
float ai = 1 / (m_ab * safe_sqrtf((1 - cosNI * cosNI) / (cosNI * cosNI)));
float G1i = ai < 1.6f ? (3.535f * ai + 2.181f * ai * ai) / (1 + 2.276f * ai + 2.577f * ai * ai) : 1.0f;
float G = G1o * G1i;
/* see eval function for derivation */
@@ -804,7 +989,7 @@ ccl_device int bsdf_microfacet_beckmann_sample(const ShaderClosure *sc, float3 N
#ifdef __RAY_DIFFERENTIALS__
float3 dRdx, dRdy, dTdx, dTdy;
#endif
float m_eta = sc->data1;
float m_eta = sc->data2;
bool inside;
fresnel_dielectric(m_eta, m, I, &R, &T,
@@ -821,14 +1006,14 @@ ccl_device int bsdf_microfacet_beckmann_sample(const ShaderClosure *sc, float3 N
*domega_in_dy = dTdy;
#endif
if(m_ab <= 1e-4f || fabsf(m_eta - 1.0f) < 1e-4f) {
if(fmaxf(alpha_x, alpha_y) <= 1e-4f || fabsf(m_eta - 1.0f) < 1e-4f) {
/* some high number for MIS */
*pdf = 1e6f;
*eval = make_float3(1e6f, 1e6f, 1e6f);
}
else {
/* eq. 33 */
float alpha2 = m_ab * m_ab;
float alpha2 = alpha_x * alpha_y;
float cosThetaM2 = cosThetaM * cosThetaM;
float cosThetaM4 = cosThetaM2 * cosThetaM2;
float tanThetaM2 = 1/(cosThetaM2) - 1;
@@ -838,7 +1023,7 @@ ccl_device int bsdf_microfacet_beckmann_sample(const ShaderClosure *sc, float3 N
float cosNI = dot(N, *omega_in);
/* eq. 26, 27: now calculate G1(i,m) */
float ai = 1 / (m_ab * safe_sqrtf((1 - cosNI * cosNI) / (cosNI * cosNI)));
float ai = 1 / (alpha_x * safe_sqrtf((1 - cosNI * cosNI) / (cosNI * cosNI)));
float G1i = ai < 1.6f ? (3.535f * ai + 2.181f * ai * ai) / (1 + 2.276f * ai + 2.577f * ai * ai) : 1.0f;
float G = G1o * G1i;

5
intern/cycles/kernel/kernel_types.h
View File

@@ -534,10 +534,7 @@ typedef struct ShaderClosure {
float3 T;
#endif
#ifdef __HAIR__
float offset;
#endif
float data2;
#ifdef __OSL__
void *prim;
#endif

4
intern/cycles/kernel/osl/osl_closures.cpp
View File

@@ -158,7 +158,7 @@ BSDF_CLOSURE_CLASS_BEGIN(HairReflection, hair_reflection, hair_reflection, LABEL
CLOSURE_FLOAT_PARAM(HairReflectionClosure, sc.data1),
#ifdef __HAIR__
CLOSURE_FLOAT3_PARAM(HairReflectionClosure, sc.T),
CLOSURE_FLOAT_PARAM(HairReflectionClosure, sc.offset),
CLOSURE_FLOAT_PARAM(HairReflectionClosure, sc.data2),
#else
CLOSURE_FLOAT3_PARAM(HairReflectionClosure, sc.N),
CLOSURE_FLOAT_PARAM(HairReflectionClosure, sc.data1),
@@ -171,7 +171,7 @@ BSDF_CLOSURE_CLASS_BEGIN(HairTransmission, hair_transmission, hair_transmission,
CLOSURE_FLOAT_PARAM(HairTransmissionClosure, sc.data1),
#ifdef __HAIR__
CLOSURE_FLOAT3_PARAM(HairReflectionClosure, sc.T),
CLOSURE_FLOAT_PARAM(HairReflectionClosure, sc.offset),
CLOSURE_FLOAT_PARAM(HairReflectionClosure, sc.data2),
#else
CLOSURE_FLOAT3_PARAM(HairReflectionClosure, sc.N),
CLOSURE_FLOAT_PARAM(HairReflectionClosure, sc.data1),

8
intern/cycles/kernel/osl/osl_shader.cpp
View File

@@ -181,12 +181,9 @@ static void flatten_surface_closure_tree(ShaderData *sd, int path_flag,
sc.T = bsdf->sc.T;
sc.data0 = bsdf->sc.data0;
sc.data1 = bsdf->sc.data1;
sc.data2 = bsdf->sc.data2;
sc.prim = bsdf->sc.prim;
#ifdef __HAIR__
sc.offset = bsdf->sc.offset;
#endif
/* add */
if(sc.sample_weight > CLOSURE_WEIGHT_CUTOFF && sd->num_closure < MAX_CLOSURE) {
sd->closure[sd->num_closure++] = sc;
@@ -202,6 +199,7 @@ static void flatten_surface_closure_tree(ShaderData *sd, int path_flag,
sc.type = CLOSURE_EMISSION_ID;
sc.data0 = 0.0f;
sc.data1 = 0.0f;
sc.data2 = 0.0f;
sc.prim = NULL;
/* flag */
@@ -219,6 +217,7 @@ static void flatten_surface_closure_tree(ShaderData *sd, int path_flag,
sc.type = CLOSURE_AMBIENT_OCCLUSION_ID;
sc.data0 = 0.0f;
sc.data1 = 0.0f;
sc.data2 = 0.0f;
sc.prim = NULL;
if(sd->num_closure < MAX_CLOSURE) {
@@ -232,6 +231,7 @@ static void flatten_surface_closure_tree(ShaderData *sd, int path_flag,
sc.type = CLOSURE_HOLDOUT_ID;
sc.data0 = 0.0f;
sc.data1 = 0.0f;
sc.data2 = 0.0f;
sc.prim = NULL;
if(sd->num_closure < MAX_CLOSURE) {

30
intern/cycles/kernel/svm/svm_closure.h
View File

@@ -24,6 +24,7 @@ ccl_device void svm_node_glass_setup(ShaderData *sd, ShaderClosure *sc, int type
if(refract) {
sc->data0 = eta;
sc->data1 = 0.0f;
sc->data2 = 0.0f;
sd->flag |= bsdf_refraction_setup(sc);
}
else
@@ -31,7 +32,8 @@ ccl_device void svm_node_glass_setup(ShaderData *sd, ShaderClosure *sc, int type
}
else if(type == CLOSURE_BSDF_MICROFACET_BECKMANN_GLASS_ID) {
sc->data0 = roughness;
sc->data1 = eta;
sc->data1 = roughness;
sc->data2 = eta;
if(refract)
sd->flag |= bsdf_microfacet_beckmann_refraction_setup(sc);
@@ -40,7 +42,8 @@ ccl_device void svm_node_glass_setup(ShaderData *sd, ShaderClosure *sc, int type
}
else {
sc->data0 = roughness;
sc->data1 = eta;
sc->data1 = roughness;
sc->data2 = eta;
if(refract)
sd->flag |= bsdf_microfacet_ggx_refraction_setup(sc);
@@ -135,11 +138,13 @@ ccl_device void svm_node_closure_bsdf(KernelGlobals *kg, ShaderData *sd, float *
if(roughness == 0.0f) {
sc->data0 = 0.0f;
sc->data1 = 0.0f;
sc->data2 = 0.0f;
sd->flag |= bsdf_diffuse_setup(sc);
}
else {
sc->data0 = roughness;
sc->data1 = 0.0f;
sc->data2 = 0.0f;
sd->flag |= bsdf_oren_nayar_setup(sc);
}
}
@@ -151,6 +156,7 @@ ccl_device void svm_node_closure_bsdf(KernelGlobals *kg, ShaderData *sd, float *
if(sc) {
sc->data0 = 0.0f;
sc->data1 = 0.0f;
sc->data2 = 0.0f;
sc->N = N;
sd->flag |= bsdf_translucent_setup(sc);
}
@@ -162,6 +168,7 @@ ccl_device void svm_node_closure_bsdf(KernelGlobals *kg, ShaderData *sd, float *
if(sc) {
sc->data0 = 0.0f;
sc->data1 = 0.0f;
sc->data2 = 0.0f;
sc->N = N;
sd->flag |= bsdf_transparent_setup(sc);
}
@@ -179,7 +186,8 @@ ccl_device void svm_node_closure_bsdf(KernelGlobals *kg, ShaderData *sd, float *
if(sc) {
sc->N = N;
sc->data0 = param1;
sc->data1 = 0.0f;
sc->data1 = param1;
sc->data2 = 0.0f;
/* setup bsdf */
if(type == CLOSURE_BSDF_REFLECTION_ID)
@@ -211,12 +219,14 @@ ccl_device void svm_node_closure_bsdf(KernelGlobals *kg, ShaderData *sd, float *
if(type == CLOSURE_BSDF_REFRACTION_ID) {
sc->data0 = eta;
sc->data1 = 0.0f;
sc->data2 = 0.0f;
sd->flag |= bsdf_refraction_setup(sc);
}
else {
sc->data0 = param1;
sc->data1 = eta;
sc->data1 = param1;
sc->data2 = eta;
if(type == CLOSURE_BSDF_MICROFACET_BECKMANN_REFRACTION_ID)
sd->flag |= bsdf_microfacet_beckmann_refraction_setup(sc);
@@ -302,11 +312,12 @@ ccl_device void svm_node_closure_bsdf(KernelGlobals *kg, ShaderData *sd, float *
sc->data1 = roughness/(1.0f - anisotropy);
}
sc->data2 = 0.0f;
if (type == CLOSURE_BSDF_ASHIKHMIN_SHIRLEY_ID)
sd->flag |= bsdf_ashikhmin_shirley_setup(sc);
else
sd->flag |= bsdf_ward_setup(sc);
#else
sd->flag |= bsdf_diffuse_setup(sc);
#endif
@@ -322,6 +333,7 @@ ccl_device void svm_node_closure_bsdf(KernelGlobals *kg, ShaderData *sd, float *
/* sigma */
sc->data0 = clamp(param1, 0.0f, 1.0f);
sc->data1 = 0.0f;
sc->data2 = 0.0f;
sd->flag |= bsdf_ashikhmin_velvet_setup(sc);
}
break;
@@ -335,6 +347,7 @@ ccl_device void svm_node_closure_bsdf(KernelGlobals *kg, ShaderData *sd, float *
sc->N = N;
sc->data0 = param1;
sc->data1 = param2;
sc->data2 = 0.0f;
if (type == CLOSURE_BSDF_DIFFUSE_TOON_ID)
sd->flag |= bsdf_diffuse_toon_setup(sc);
@@ -369,11 +382,11 @@ ccl_device void svm_node_closure_bsdf(KernelGlobals *kg, ShaderData *sd, float *
sc->N = N;
sc->data0 = param1;
sc->data1 = param2;
sc->offset = -stack_load_float(stack, data_node.z);
sc->data2 = -stack_load_float(stack, data_node.z);
if(!(sd->type & PRIMITIVE_ALL_CURVE)) {
sc->T = normalize(sd->dPdv);
sc->offset = 0.0f;
sc->data2 = 0.0f;
}
else
sc->T = sd->dPdu;
@@ -418,6 +431,7 @@ ccl_device void svm_node_closure_bsdf(KernelGlobals *kg, ShaderData *sd, float *
sc->sample_weight = sample_weight;
sc->data0 = radius.x;
sc->data1 = texture_blur;
sc->data2 = 0.0f;
sc->T.x = sharpness;
#ifdef __OSL__
sc->prim = NULL;
@@ -434,6 +448,7 @@ ccl_device void svm_node_closure_bsdf(KernelGlobals *kg, ShaderData *sd, float *
sc->sample_weight = sample_weight;
sc->data0 = radius.y;
sc->data1 = texture_blur;
sc->data2 = 0.0f;
sc->T.x = sharpness;
#ifdef __OSL__
sc->prim = NULL;
@@ -450,6 +465,7 @@ ccl_device void svm_node_closure_bsdf(KernelGlobals *kg, ShaderData *sd, float *
sc->sample_weight = sample_weight;
sc->data0 = radius.z;
sc->data1 = texture_blur;
sc->data2 = 0.0f;
sc->T.x = sharpness;
#ifdef __OSL__
sc->prim = NULL;